Is it important to have a second child?

Q:My daughter is 3 and half years old. Is it necessary to have a second child so that my daughter will not feel lonely in future?

A:We are only human beings trying to help with everyday problems, not people who like to play God!
It is entirely a decision of the parents. There are no rules. Many adults remember the fun of growing up with sisters and brothers. Maybe some remember they that did not get on with their siblings. Each family has its own history.
Sometimes only children complain of feeling lonely. Sometimes only children make a lot of friends and are close to their cousins. I cannot say that having another child is necessary in any sense. You must have a reason for asking this question and you both will have to discuss it and work out what you wish.